Mathematics 10 — Exercise 3.4 · Q1 (iii) BA

Full question

Find BA, if possible.

Step-by-step solution

1. 2 columns in the first matrix match 2 rows in the second. The product has 1 rows and 1 columns.

   $$(\left[\begin{array}{cc}2& 5\end{array}\right],\left[\begin{array}{c}4\\ 4\end{array}\right])$$

2. Entry (1,1): pair row 1 with column 1 and add their products.

   $$2\times 4+5\times 4$$

3. Calculate this individual product, including its signs.

   $$2\times 4=8$$

4. Calculate this individual product, including its signs.

   $$5\times 4=20$$

5. Add the calculated products to obtain this entry.

   $$8+20=28$$

6. Place the calculated entries in their original row and column positions.

   $$\left[\begin{array}{c}28\end{array}\right]$$

Answer

The final answer is shown below.